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General Aviation Safety
On January 9, 1997, an Empresa Brasileira de Aeronautica, S/A (Embraer) EMB-120RT, operated by COMAIR Airlines, Inc., crashed during a rapid descent after an uncommanded roll excursion near Monroe, Michigan. The flight was a scheduled, domestic passenger flight from the Cincinnati/Northern Kentucky International Airport, Covington, Kentucky, to Detroit Metropolitan/Wayne County Airport, Detroit, Michigan. The flight departed Covington with 2 flightcrew, 1 flight attendant, and 26 passengers on board. There were no survivors. The airplane was destroyed by ground impact forces and a postaccident fire. IMC prevailed at the time of the accident, and the flight was operating on an IFR flight plan.The probable cause of this accident was the FAA's failure to establish adequate aircraft certification standardds for flight in icing conditions.
TO THE FEDERAL AVIATION ADMINISTRATION: Actively pursue research with airframe manufacturers and other industry personnel to develop effective ice detection/protection systems that will keep critical airplane surfaces free of ice; then require their installation on newly manufactured and in service airplanes certificated for flight in icing conditions.
Original recommendation transmittal letter:
Closed - Unacceptable Action
MONROE, MI, United States
In-Flight Icing Encounter and Uncontrolled Collision with Terrain, Comair Flight 3272, Embraer EMB-120RT, N265CA
Addressee(s) and Addressee Status:
FAA (Closed - Unacceptable Action)
Safety Recommendation History
[Response to FAA NPRM 2004-NM-36-AD, 5/28/2004] Notation 7637: The National Transportation Safety Board has reviewed the Federal Aviation Administration (FAA) Notice of Proposed Rulemaking, "Airworthiness Directives; Empresa Brasileira Aeronautica S.A. (EMBRAER) Model EMB-135BJ and EMB-145XR Series Airplanes," Docket No. 2004-NM-36-AD, published in the Federal Register (Vol. 69, No. 85) on May 3, 2004. The notice proposes the adoption of a new airworthiness directive (AD) that is applicable to certain EMBRAER airplanes and that would require the installation of an additional indication device (a lamp on the instrument panel) to the clear ice indication system. The discussion of the notice states that the Departamento de Aviacao Civil (DAC), which is the airworthiness authority for Brazil, has notified the FAA of an unsafe condition that may exist on certain EMBRAER Model EMB-135BJ and EMB-145XR series airplanes. The DAC advises that a risk assessment has shown that the reliability level of the clear ice indication system is not sufficient to comply with the requirements established for the system. This condition, if not corrected, could result in undetected in-flight buildup of clear ice on airplane control surfaces, which could lead to reduced controllability of the airplane. The reliability problem identified by the DAC relates to the function of the indication system that alerts pilots after ice is detected, and not with the performance or operation of the icing sensor itself. The clear ice indication system sensor is a flush-mounted, vibrating type ice detector that is installed on the top surface of both wings of the EMB-135BJ and EMB-145XR to detect the presence of clear ice on the top surface of the wings. The addition of the indication lamp on the instrument panel will provide a redundant indicator to the current clear ice detection message displayed on the Engine and Instrument Crew Alerting System (EICAS). The DAC issued airworthiness directive AD No. 2004-01-01 on January 27, 2004, requiring the installation of an additional indication device to the clear ice indication system to ensure the continued airworthiness of these airplanes in Brazil. Instructions and procedures to accomplish the AD are described in Embraer Service Bulletins No. 145-30-0035 (Revision 01) for the EMB 145XR and No. 145LEG-30-0002 for the EMB?135BJ. The location and function of the clear ice detection system on the EMB-135BJ and EMB?145XR are a relatively new type of installation and operation, and the FAA should encourage other manufacturers to use enhanced ice detection systems similar to this one. Development of advanced ice detection and protection systems was the subject of Safety Board Recommendation A-98-93, which was classified Closed-Unacceptable Action on March 12, 2001, and which recommended the FAA to accomplish the following: Actively pursue research with airframe manufacturers and other industry personnel to develop effective ice detection/protection systems that will keep critical airplane surfaces free of ice; then require their installation on newly manufactured and in-service airplanes certificated for flight in icing conditions. The Safety Board believes that airworthiness directive action is warranted for any improvements to icing detection and indication systems that will give flight crews accurate information that enables them to recognize undetected or unnoticed airframe icing quickly. The Safety Board continues to believe that airframe structural icing is an important safety issue, and airframe structural icing remains on our Most Wanted list of transportation safety improvements. The Safety Board agrees with the proposed airworthiness directive and believes that the FAA should require installation of the additional indication device on the Model EMB-135BJ and EMB-145XR Series Airplanes as described in the applicable EMBRAER service bulletins.
The Safety Board is disappointed that the FAA disagrees with the need for the recommended research and activities and that the FAA does not plan to take any action. The Board notes that icing accidents it has investigated in the last 10 years, including United Express flight 2415, a British Aerospace Jetstream that crashed in Pasco, Washington; American Eagle flight 4184, an ATR-72 that crashed in Roselawn, Indiana; and the accident that prompted this recommendation, all demonstrate that despite the icing certification requirements, aircraft became uncontrollable and crashed when ice accumulated on critical surfaces. Because the FAA does not plan to pursue the recommended action, Safety Recommendation A-98-93 is classified Closed--Unacceptable Action.
Letter Mail Controlled 10/02/2000 3:16:36 PM MC# 2001437 In its letter dated March 9, 2000, the Board asked that the FAA pursue research to develop ice detection/protection systems so critical airplane surfaces are kept free of any ice accumulation. The Board further stated that it believes adequate safety margins do not always exist with present deicing systems, and that FAA should assume a leadership role in developing new and effective ice detection/protection equipment rather than allowing private industry to be the primary agent of research. Since 14 CFR 121.629(b) currently requires that critical surfaces be free of ice, frost, or snow prior to takeoff, the FAA will address this recommendation as it pertains to "inflight" operations. The FAA does not agree that the critical airplane surfaces must be kept free of ice accumulation during inflight operations. 14 CFR Part 25 requires that an airplane must be shown to operate safely in icing conditions defined by Federal Aviation Regulations. The regulations do not preclude certification of an airplane with ice accretions on the critical surfaces. In its letter dated March 9, 2000, the Board also questioned the adequacy of safety margins with ice protection systems that allow ice to form on the airframe. The FAA recognizes the need for improved regulations to ensure safe operations in icing conditions. In response to Safety Recommendation A-96-54, the Flight Test Harmonization Working Group has developed proposed regulatory changes to 14 CFR Part 25 flight requirements that will clearly define what is meant by the term "safely operate." The proposed certification process will require evaluation of airplane performance and handling characteristics with the ice accretions that form in all phases of flight, including those that would accrete on protected surfaces .prior to activation of the ice protection systems. These changes address the Board's concern of adequate safety margins with ice protection systems that allow ice to form on the airframe. Since it is possible to demonstrate safe operations with ice accumulations on the airframe, the FAA does not agree that devices need to be required that keep critical airplane surfaces free of ice and does not plan to fund research in this area. The FAA believes that the current regulations to require that an airplane must be shown to operate safely in icing conditions address the full intent of this safety recommendation. I consider the FAA's action to be completed on this safety recommendation.
THE SAFETY BOARD DOES NOT BELIEVE THAT THE FAA'S RESPONSE ADEQUATELY ADDRESSES A-98-93, WHICH ASKED THE FAA TO ACTIVELY PURSUE RESEARCH TO DEVELOP ICE DETECTION/PROTECTION SYSTEMS. THE SAFETY BOARD BELIEVES THAT ADEQUATE SAFETY MARGINS DO NOT ALWAYS EXIST WITH PRESENT DEICING SYSTEMS, AS DEMONSTRATED BY THE LARGE NUMBER OF SERIOUS ACCIDENTS AND INCIDENTS DUE TO ICE ACCUMULATION. IT IS OUR VIEW THAT THESE SYSTEMS SHOULD BE DESIGNED SO THAT CRITICAL AIRPLANE SURFACES ARE KEPT FREE OF ANY ICE ACCUMULATION. THE BOARD STRONGLY ENCOURAGES THE FAA TO ASSUME A LEADERSHIP ROLE IN DEVELOPING NEW AND EFFECTIVE ICE DETECTION/PROTECTION EQUIPMENT RATHER THAN ALLOWING PRIVATE INDUSTRY TO BE THE PRIMARY AGENT OF RESEARCH. ALTHOUGH THE FAA HAS STATED THAT IT INTENDS NO FURTHER ACTION, A-98-93 IS CLASSIFIED "OPEN--UNACCEPTABLE RESPONSE," PENDING FURTHER RESPONSE ON THIS ISSUE.
THE ICE DETECTION AND PROTECTION SYSTEMS ON NEWLY MANUFACTURED AND IN-SERVICE AIRPLANES SATISFY THE REGULATORY REQUIREMENTS FOR FLIGHT IN ICING CONDITIONS AND, IN MANY CASES, ARE STATE OF THE ART. THE USE AND EFFECTIVENESS OF THESE SYSTEMS MUST BE CONSIDERED IN THE TOTAL CONTEXT OF THE FLIGHTCREW OPERATIONAL PROCEDURES, PILOT TRAINING PROGRAMS, AND PROGRAMS TO PROVIDE CURRENT AND ACCURATE WEATHER INFORMATION TO FLIGHTCREWS. THIS TOTAL REQUIREMENT APPROACH TO ADDRESSING ICING ISSUES IS REFLECTED IN THE FAA'S IN-FLIGHT AIRCRAFT ICING PLAN. THE FAA DOES AND WILL CONTINUE TO SUPPORT CERTIFICATION OF NEW AND INNOVATIVE ICE DETECTION AND PROTECTION SYSTEMS, AND ENCOURAGES RESEARCH AND DEVELOPMENT OF INNOVATIVE TECHNOLOGIES. THE FAA ALSO WORKS CLOSELY WITH INDUSTRY IN PARTNERSHIP EFFORTS TO UPGRADE THE LEVEL OF SAFETY FOR THE FLYING PUBLIC. AN EXAMPLE IS THE "WEEPING" LEADING EDGE ICE PROTECTION SYSTEM THAT HAS BEEN CERTIFIED ON SEVERAL 14 CFR PART 23 AIRPLANES AND 14 CFR PART 25 BUSINESS JETS. HOWEVER, THE LEADERSHIP ROLE, FUNDING, AND DEVELOPMENT OF RESEARCH INITIATIVES ARE PRIMARILY VESTED IN PRIVATE INDUSTRY. AS THE REGULATORY AGENCY, THE FAA GENERALLY LIMITS ITS FUNDING TO RELATED APPLICATIONS LIKE NEW REGULATORY STANDARDS AND ADVISORY MATERIAL TO ENSURE THE SAFE OPERATION OF AIRPLANES THAT INCORPORATE NEW TECHNOLOGY ADVANCEMENTS. IN SOME INSTANCES, THE FAA HAS COMBINED RESOURCES WITH OTHER GOVERNMENT AGENCIES TO SUPPORT PRIVATE INDUSTRY IN DEVELOPING TECHNOLOGIES THAT WILL PROVIDE SAFETY BENEFITS FOR ALL PARTIES INVOLVED. AN EXAMPLE OF SUCH RESEARCH AND DEVELOPMENT FUNDING IS THE COLLABORATION OF THE FAA, NASA, DEPT. OF DEFENSE, AND PRIVATE INDUSTRY TO INVESTIGATE POSSIBILITIES FOR AIRBORNE REMOTE DETECTION OF ICING CONDITIONS. THIS EFFORT IS INCLUDED IN ONE ELEMENT OF THE FAA'S IN-FLIGHT AIRCRAFT ICING PLAN PUBLISHED IN APRIL 1997. CURRENT CERTIFICATION PRACTICES ENSURE, REGARDLESS OF THE MECHANISM USED FOR ICE PROTECTION, ADEQUATE OPERATIONAL SAFETY MARGINS EXIST. ONGOING EFFORTS BY THE AVIATION RULEMAKING ADVISORY COMMITTEE (APAC), BY THE ICE PROTECTION HARMONIZATION WORKING GROUP AND THE FLIGHT TEST HARMONIZATION WORKING GROUP, WILL DETERMINE WHETHER ICE DETECTION EQUIPMENT SHOULD BE REQUIRED AND WHAT, IF ANY, ADDITIONAL OPERATIONAL REQUIREMENTS NEED TO BE IN PLACE TO ENSURE SAFE AIRCRAFT OPERATION IN ICING CONDITIONS. HOWEVER, NEW SYSTEMS WILL NOT BE MANDATED AUTOMATICALLY FOR INSTALLATION ON NEW AIRPLANES OR BE RETROFITTED ON IN-SERVICE AIRPLANES UNLESS THERE IS SPECIFIC DETERMINATION OF BENEFIT FOR EACH SYSTEM. I PLAN NO FURTHER ACTION IN RESPONSE TO THIS SAFETY RECOMMENDATION.
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